To reduce power consumption, ventilation devices mounted in electrical devices such as ventilators have increasingly adopted a brushless DC motor. The brushless DC motor is classified into two types, i.e., the motor including a driving circuit board, and the motor driven by an external circuit without including the driving circuit board.
The motor including the driving circuit board can be driven merely by feeding power to the motor, which is convenient, but becomes complex in structure. Moreover, in the case where the device includes a control circuit board other than the driving circuit board in the motor, the two circuit boards are present in the device.
The motor that does not include the driving circuit board has a simple structure, but requires a separate driving circuit. However, in the case where the device has another control circuit board, the motor driving circuit can be mounted on the control circuit board so that the circuit boards in the device are unified into one circuit board.
The conventional brushless DC motor including this type of driving circuit board is configured as follows (refer to PTL 1, for example).
The conventional brushless DC motor will be described below with reference to FIG. 16 and FIG. 17.
As illustrated in a stator structure in FIG. 16, a stator includes a plurality of stacked stator cores 101, insulator 102 forming an insulating layer on a surface of stator cores 101, and outer peripheral holes 106 for vertically receiving terminal pins formed on insulator 102 on an outer circumference of stator cores 101. Insulator 102 on the outer circumference of stator cores 101 has board holders 108a, 108b for holding driving circuit board 107 (FIG. 17). These components constitute the stator.
As illustrated in FIG. 17, in the conventional brushless DC motor, winding wound via insulator 102 is connected to terminal pin 110 vertically received in outer peripheral hole 106, and terminal pin 110 is connected to driving circuit board 107 held by board holders 108a, 108b. Then, in the state where driving circuit board 107 is connected to connector terminal 109 of connector 103 held on driving circuit board 107, the stator is coated with mold resin 105 to form an outer package of the motor. Subsequently, rotor 104, shaft 111, and bearings 112a, 112b, which are integrated, are placed in the outer package of the motor, and are covered with bracket 113.